The invention relates to a valve drive train actuating device having at least one firing camshaft, which can be phase shifted relative to a crankshaft by means of a firing camshaft adjusting device and a decompression brake device comprising at least one brake cam and at least one decompression valve.
Valve drive train actuating devices, particularly for internal combustion engines having at least one firing camshaft, which can be phase-shifted with respect to a crank-shaft by means of a firing camshaft adjusting device, which has also a decompression brake device comprising at least one braking cam and at least one decompression valve, are already known.
It is the principal object of the present invention to provide a decompression brake device with a maximum braking performance in different engine operating states.